The Sony DT 55-300mm F4.5-5.6 SAM is a telephoto zoom lens designed for use with Sony's APS-C format SLT cameras, which offers an effective focal length range of approximately 80-450mm. Optical construction includes an ED (Extra-Low Dispersion) element, which should reduce aberrations and increase sharpness, and a built-in SAM focus motor provides fast, if not completely silent autofocus.